I’ve found that if you have access to CAD, it’s always better to design as much of the final project in virtual first.

This has a lot of advantages:

• Stuff just fits on the first try if you model it accurately

• You can save money by knowing the exact components going into the build

• You get to preview what it’ll look like, and make changes before committing

I’m printing the initial case (top and bottom) without the details like bosses and mounting points, just to get it in my hands and see if it’s comfortable to hold and easy to store.

Some of the initial design details:

• Clamshell case for the top and bottom

• Mounting bosses for assembly

• Double-checked that the OLED screen’s PCB will fit in the space provided

I still need to add an external charging port (likely USB-C). I’ll see if this can handle data too—if not, I might add an SD card slot as an easy way to store the collected data.

Next, I’ll see if there’s enough room for the main components: the dev board, battery, Pocket Geiger, and other sensors. There will likely be at least two custom PCBs—one for the switches, and one for the bulk of the sensors. If everything fits well, I probably won’t try to make it smaller; I want it to feel substantial in the hand.